Multispeed transmission



March 6, 1951 F. w. PORTER 2,544,543

MULTISPEEDTRANSMISSION Filed Oct. l, 1949 3 Sheets-Sheet 1 INVENTOR. FRANCIS w. FEIRTER.

' ATTDFQNEY March 6, 1951 F. w. PORTER 2,544,543

MULTISPEED TRANSMISSION Filed Oct. l, 1949 5 Sheets-Sheet 2 '524ha u I gy: 74 86 100 'F1 I I I E- w 4. 4V/v4 4.4i

Li a 88 mgljj' FRANCE I/ggge'm.

52 TE-E Ri-UAM ATTRNEY March 6, 1951 F. w. PORTER 2,544,543

MULTISPEED TRANSMISSION Filed Oct. l, 1949 3 Sheets-Sheet 3 IN VENTOR. FRANC l5 W. PDRTER BY MJL. @JL

ATTRNEY Patented Mar. 6, 1951 FranjcisfW. Porter, Marshfield, Mass., assigner to Corporation, a corporayWright Aeronautical application october 1, 1949, serial 119,044

SC'laims. 1 VThis invention `relates to `multi-#speed transmissions and is .particularly directed to the type of vtransmission illustrated 'in copendi-ng application 'Serial No. 609,432, led August 7, '1945, in vthe name ofDaviset al.

vThe transmission described in said copending application has been used on aircraft engines as va two-speed transmission for their engine driven superchargers. Said transmissions `'have perlformed satisfactorily except for the short life, in certain installations, of the loneway roller clutch employed thereinl An object of the present in vention comprises the provision of a Atwo-speed transmisson'having theadvantages of the twospeed transmission described in said copendng application l'but in which the one-way roller clutch of said prior transmission has been eliminated. In accordance withthe present invention the one-way roller clutch of said prior transmission has been replaced in a novel 'ma-nner by a one-way jaw clutch.

Other objects of the invention will become `apparent upon reading the lannexed Vdetailed description in connection with the drawing in which: l

Figure .1 is ran axial sectional View of aetransmission embodying the invention;

Figure 2 is a side view .partlyy in section of a synchronizer ring Vformi-ng (part of a one-way jaw clutchincorporated `inFigure 1 l Figure 3 is an lend view partly `in section of said synchronizer ring as Viewed vfrom the right of l'igures land-2;

VFigure 4 is an end viewof the one-Way jaw clutch member Yas viewed from the right in Figurelx. l f

Figure 5 is -a `sectional view taken along line 5-55 of Figure 4;

V'ligure 6 isa sectional View taken along line Sk8 ofvFigure v-1; and F'gure 7 is an end viewcf the transmissionim put shaitas viewed from the Yleftin Figure l and illustrating the `planet .pinions carried by said "The inventionhasbeen designed `for use as 'a two-speed drive-for the 'superchargercf an ai-r= craft internal 'combustion engine, As will Valp-- pear-, however, the inventionisnotlmited to this specific use and instead i` `general application.

YReferring to the 'd ing, an engine (not shown) `is drivably connected to a shaft lu for driving said shaft clockwise 'when viewed from the right in 'Figure `1. The shaft 'It has a radially extending annuiar flange r2 vand an annular 'member I4 `is rigidly secured tesai'ci shaft iian'gje -2 I2 by bolts IB. A 'gear I8 is also secured tothe 'shaft ange l2 by the bolts I6, said gear being provided for driving various accessories of the nll.

The annular input 'shaft member I4 has `a plurality of circumferentiauy spaced studs 28 eX- tending therefrom and planet pinions 22 are j'ournaled on the studs 28,.`said pinions being secured thereon by the bolts VI6. Each pinion 22 is disposed in meshing engagement with an internal gear 24 and ywith a "sun gear 26, said sun gears being concentric. The internal 'gear 24 is secured against rotation 'to a xed housing 28 by screws 38 whereby a step-up drive is provided from the engine driven yshaft l0 to lthe sun `gear 26. Pifeiablyth internal gear 24 is Secured to the fixed housing 28 through a exible connection "as described in 'said copending application.

The vs'un gear .26 is' formed integral With an internal gear 32 which forms the input member of a planetary gear train. A shaft 34 has a sun gear 36 which forms the output member of said planetary gear train. A composite planet pinion carrier comprising members 38 and 48 is secured together by bolts 42. The 'carrier member .4Q has a plurality of circumferentially spaced pairs of studs '44 and Vlli about which a .plurality of pairs of planet p inion's 48 and 58, respectively, are journa1ed. The planet pinions "48 and 50 of each pair are disposed in meshing engagement with eachother and each pinion 48 is also disposed in meshing engagement with 'the sun gear 38 while each pinion 58 is also disposed in meshing en -ga'gement with the internal gear 32. This structure of the planetary vgear train is more fully described in connection with Figure 5 of said co- Dldih'g application.

A plurality of annular friction brake plates52 are vspli'ned te and 'are disposed about an annular rim 54 integral with the planet carrier member 38,

All'anfnilar drum 5B is secured to the Xed housing y28 by screws 58. Aplurality of "annular friction brake plates BD 'are splined to and are disposed internally "of the ann'ular` drum 56. The l'riction brake plates 52 and 68 are alternately dis- 'posed `s' that when said plates are clamped tog'thr r'the composite pinion carrier member is 'n eid against rtatcn to the nxed housing 23 whereupon 'a step-up vspeed ratio drive is provided :from the'input member 32 lto the output shaft '34, said composite pinion carrier providing the reaction torque for said step-up drive.

Irl order to engage the friction brake plates 52 vand en, a piston tz is slidabie, to clamp the brake 'plates between said piston e2 and a, backing plate 54. A suitable fluid, such as engine lubricating oil, is adapted to be supplied under pressure against the pisto-n 62 through a passage 66 under the control of a valve 68. In the full line position of the valve 68, as illustrated in Figure 1, the passage 66 is connected to a drain passage 'I0 whereupon the friction brake plates 52 and 60 are disengaged. When the valve is moved to its dotted-line position, the passage 66 is connected to a fluid pressure supply passage I2 whereupon said fluid pressure acts against the piston 62 to clamp the friction brake plates 52 and 60 together.

When the friction brake plates clamped together to hold the composite pinion carrier 38, 40 against rotation, a relatively high step-up speed ratio drive is provided from the input shaft I V to the output shaft 34, said com- 'posite pinion carrier providing the reaction torque for said drive. If the friction brake plates 52 and 60 are now disengaged, the composite planet carrier member 38, 40 isrotated by and in. the direction of said reaction torque. Means are provided to constrain said pinion carrier member to rotation at the speed of the input shaft I0 thereby providing a relatively low stepup speed ratio drive from the input shaft I8 to the output shaft 34. In said copending application a one-way clutch is provided for this latter purpose whereas in accordance with the present invention a positive one-way toothed or 'jaw clutch is provided for this purpose. Except for this difference in clutch structure the transmis- 52 and 60 are` sion herein disclosed is substantially the same as that disclosed in Figure 5 of said copending application.

The positive toothed clutch of the present invention comprises an annular clutch member 'I4 axially splined ,to an adapter ring 16 which in turn is axially splined to the hub 18 of the pin-- ion carrier member 40 for rotation therewith. The clutch member 'I4 is provided with left-hand external helical splines or threads 80 meshing with corresponding internal helical splines or threads 82 on a synchronizer ring 84. The clutch member 'I4 is also provided with axially extending jaws 86 adapted to mesh with the corresponding jaws 88 formed on the adjacent side of the input shaft flange I2. The nature of these jaws is best seen in Figure 6.

The synchronizer ring 84 is loosely disposed within the annular input shaft member |4. In addition the synchronizer ring 84 has an annular radially extending flange 90 extending loosely into an annular groove formed between the input shaft member I 4 and the input shaft flange I2 to prevent axial movement of the synchronizer ring 84 relative to the input shaft I0 while permitting rotation of said ring relative to said input shaft. A pair of split rings 92 are fitted within external annular grooves extending about the synchronizer ring 84. Each of the split rings 92 has a head 94 fitted within a cross slot 96 in the synchronizer ring to prevent rotation of the split rings relative to the synchronizer. ring. The split rings 92 are made with a bias ,which causes them to expand against the interior surface of the annular input shaft member I4 regardless of whether said synchronizer ring'84 creasing speed in the same direction as the input shaft |0. 'I'he clutch member 'I4 and synchronizer ring 84 rotate with the composite pinion carrier 38, 40. As long as the input shaft member I4 is rotating faster than the clutch member 'I4 and the synchronizer ring 84, the split rings 92 are forced to contract slightly around the out side of the synchronizer ring 84. This action takes place because, as best seen in Figures 2 and 3, the split rings 92 are so installed or disposed on the synchronizer ring 84 that their free ends 9'I are pointed in the direction of rotation of the input shaft |0 whereby the higher speed of the annular input member I4 tends to cause said split rings to warp up around the outside of the synchronizer ring 84. This action tends to reduce the original bias of the split rings 92, but sufficient frictional drag still remains between the split rings 92 and the input shaft member I4 so that by means of the split ring heads 94 and the cross slots 96 this frictional drag tends to rotate the synchronizer ring clockwise (as viewed from the right in Figure 1) ahead of the clutch member I4 thereby urging the clutch member 'I4 toward the left (as viewed in Figure 1) against a shoulder 98. Y When, however, the speed of the clutch member 14 tends to exceed that of the input shaft I0, the frictional drag of the split rings 92, against the interior surface of the annular input member I4, is greatly multiplied because said split rings are forced to expand against the interior surface of the annular input member I 4. This action takes place due to the aforementioned disposition of the split rings 92 on the synchronizer ring 84. Thus as soon as the speed of the synchronizer ring 84 exceeds slightly the speed of the input shaft member I4, said split rings 92 tend to be unwrapped from around the outside of said synchronizer' ring 84 into tighter frictional engagement with the input shaft member I4. The resulting large frictional drag reacts on the synchronizer ring and, by means of the split ring heads 94 and cross slots 96, tends to reduce the speed of said synchronizer ring to the same value as that'of the input shaft I0. Thereupon, the clutch member 'I4 will shift smartly to the right along the helical splines 82 (to the position illustrated in Figure 1) thereby effecting engagement of the clutch teeth 86 and 88. Because the engageable faces of the clutch teeth 86 and 88 are undercut, as illustrated in Figure 6, the torque on said faces will pull the clutch teeth into complete engagement. When the clutch teeth 86 and 88 are engaged the composite pinion carrier member 38', 40 is restrained to rotation at the same speed as that of the input shaft I0 thereby providing a relatively low step-up speed ratio drive from the input -member 32 to the output member 34.

The faces |00 and |02 of the 'clutch teeth 86 and 88, respectively, are inclined so as to throw said teeth out of engagement when the speed of the input shaft I0 exceeds that of the clutch member 14. Thus when the friction braken l52, 60 is engaged to hold the pinion carrier member 38, 4 0 stationary, the clutch member 'I4 is also held against rotation whereby the faces A|00and |02 of thev Vclutch teeth 86 and 88 ride over each other to shift the clutch member 14 toward the shoulder 98. As previously described, the clutch member 'I4 is held against the shoulder 98 at any time the input shaft I0 has a higher speed than said clutch member. This is due to the slight frictionaljdrag occurring between the split rings 92`and the' interior surface of the 'annular input higher speed thereby holding the clutch member 14 against the shoulder 98. This prevents undue wear andpossible damage to the clutch teeth 186 and 88 during all operation inthe high step-up speed ratio. y Y

It should be apparent that the split rings 92 instead of being annular could be helically Wrapped around the synchronizer ring 84. For example the two splitl 1ings'92 could be replaced by a single helical ring wrapped around the synchronizer ring 84 with one `end anchoredto said synchronizer ring and with the free end of said helical ring pointing in the Vdirection of rotation of the input shaft lil.

The invention has been described in connection "i with a transmission similar to that illustrated in Figure 5 of said copending application. Y In accordance with the present invention a one-way jaw clutch has been. substitutedv for the onevvay roller clutch of said prior transmission. It

should be obvious that a one-Way jaw clutch could be similarly substituted for the one-Way clutch embodied in the transmission of Figure 1 of said copending application.

While I have described my invention in detail in 'its present preferred embodiment, it will be obvious to those skilled in the art, after understanding my invention, that various changes and modications may be made therein without departing from the spirit or scope thereof. I aim in the appended claims to cover all such modications.

I claim as my invention:

l. In a multi-speed transmission; a planetary gear train comprising an input member, an output member and a torque reaction member; a brake engageable to prevent rotation of said reaction member, said reaction member being arranged to rotate in the direction of the reaction torque acting thereon upon disengagement of said brake during transmission of torque by said gear train; a rotatable member; gearing connecting said rotatable member to said gear train for rotation in the direction of said reaction torque at a speed less than the speeds of said input and output members; and a one-way jaw clutch automatically engageable upon release of said brake to limit the speed of rotation of said reaction member to the speed of said rotatable member.

2. In a multi-speed transmission; a planetary gear train comprising an input member, an output member and atordue reaction member: a brake engageable to prevent rotation of said reaction member. said reaction member being arranged to rotate in the direction of the reaction toroue acting thereon upon disengagement of said brake during transmission of torque by said gear train: a rotatable member; gearing connecting said rotatable member to said gear train for rotation in the direction of said reaction torque at a speed less than the speeds of said input and output members; and a one-Way jaw clutch automatically engageable upon release of said brake to limit the speedv of rotation of said reaction member to the speed of said rotatable 6 member; `'said jaw clutch including clutchY teeth onene -of said 'reaction and rotatable members, a clutch member rotatable with the other of said reaction and rotatable members and having clutch teeth; and means including helical splines on said clutch member for moving said `clutch mem-berto eiect engagement of said clutch teeth when the speed of said reaction member tends to exceed that of said rotatable member.

3. A multi-speed transmissxm comprising an input shaft; a planetary gear train including an input member, an output'member and a rotatable torque reaction member; means providing a step-up speed ratio drive from said input shaft to said input member; a brake engageable to prevent rotation of said reaction member `to provide' a high speed ratio drive betweenxsaid input and output members, said reaction .member being arranged to rotate in the direction vof the reaction torque acting thereon upon release `of said Ybrake during transmission of torque by said gear train; `and a one-way jaw clutch automatically engageable upon release of said brake to 'limit the speed of rotation of said re-action member to the speed of said input shaft thereby providing a low speed ratio drive between said input and output members.

4. A multi-speed `transmission comprising an input shaft; a planetary gear train including an input member, an output member and a rotatable torque reaction member; means providing a stepup speed ratio drive from said input shaft to said input member; a brake engageable to prevent rotation of said reaction member to provide a high speed ratio drive between said input and output members, said reaction member being arranged to rotate in the direction of the reaction torque acting thereon upon release of said brake during transmission of torque by said gear train; and a one-way jaw clutch automatically engageable upon release of said brake to limit the speed of rotation of said reaction' member to the speed of said input shaft thereby providing a low speed ratio drive between said input and output members; said jaw clutch including clutch teeth on one of said input shaft and reaction member, a clutch member rotatable with the other of said input shaft and reaction member and having clutch teeth, and means including helical splines on said clutch member for moving said clutch member to effect engagement of said clutch teeth when the speed of said reaction member tends to exceed that of said input shaft.

5. A multi-speed transmission comprising an input shaft; a planetary gear train including an input member, an output member and a rotatable torque reaction member; means providing a stepup speed ratio drive from said input shaft to said input member; a brake engageable to prevent rotation of said reaction member to provide a high speed ratio drive between said input and output members, said reaction member being arranged to rotate in the direction of the reaction torque acting thereon upon release of said brake during transmission of torque by said gear train; and a one-Way jaw clutch automatically engageable upon release of said brake to limit the speed of rotation of said reaction member to the speed of said input shaft thereby providing a low speed ratio drive between said input and output members; said jaw clutch including a clutch member mounted for rotation with and for axial movement relative to said reaction member and for axial movement relative to said input shaft, said clutch member having clutch teeth adapted to engage and disengage corresponding clutch teeth on said input shaft in response to axial movement of said clutch member relative to said input shaft.

6. A multi-speed transmission comprising an input shaft; a planetary gear train including an input member, an output member and a rotatable torque reaction member; means providing a stepup speed ratio drive from said input shaft to said input member; a brake engageable to prevent rotation of said reaction member to provide a high speed ratio drive between said input andaoutput members, said reaction member being arranged to rotate in the direction of the reaction torque acting thereon upon release of said brake during transmission of torque by said gear train; and a one-way jaw clutch automatically engageable upon release of said brake to limit the speed of rotation of said reaction member to the speed o f said input shaft thereby providing a low speed ratio drive between said input and output members; said jaw clutch including a clutch member mounted for rotation with and for axial movement relative to said reaction member, a ring helically splined to said clutch member, axially extending jaw clutch teeth on said clutch member and input shaft, and means adapted to provide a slip drive connection between said ring and said input shaft when the speed of rotation of said clutch member tends to exceed that of said input shaft for urging said clutch member along said helical splines to eiect engagement of said clutch teeth.

7. In a multi-speed transmission as recited in claim 6 in which said slip drive connection com-A prises a split ring carried by said helically splined ring for rotation therewith, said split ring being biased into frictonal drving engagement with said input shaft.

8. In a multi-speed transmission as recited in claim 6 in which said slip drive connection comprises a split ring carried by said helically splined ring for rotation therewith, said split ring being ybiased into frictional driving engagement with said input shaft, one end of said split ring being anchored to said helically splined ring and the other end of said split ring pointing in the direction of rotation of said input shaft.

FRANCIS W. PORTER).

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS 

